Saccharides

SUGARS (and therefore CARBOHYDRATES) divided into mono-, di-, tri- and polysaccharides. Monosaccharides are the basic units, simple sugars; disaccharides, e.g., sucrose and lactose, are formed by condensing two monosaccharides and removing water. Sucrose gives, on HYDROLYSIS, a mixture of glucose and fructose; trisaccharides comprise three basic units and polysaccharides are a large class of natural carbohydrates including STARCH and CELLULOSE.

Taken from Dictionary of Science